Motor-control system.



U. KRAMER.

MOTOR CONTROL SYSTEM.

APPLICATION FILED JUNE 3, 1912.

1,042,692. Patented Oct. 29, 1912.

3 BHEETBSHEET 1.

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444 b WM 'His a ttornav c. KRKMER. MOTOR CONTROL SYSTEM. APPLICATIONFILED JUNE 3, 1912.

1,042,692. Patented 001;. 29, 1912.

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Patnted 0615. 29, 1912.

UNITED STATES PATENT OFFICE.

CHRISTIAN KRAMER, or BERLIN, GERMANY, Ass cnon TO GENERAL ELEc'rRIcCOMPANY, aconrom'rmn on NEW YORK.

moroR-coN'rRoL SYSTEM.

Specification of Letters Patent.

. Patented Oct. 29, 1912.

Application am media, 1912. Serial in. 701,118.

To all wh -0m it may concern Be it known that I, CHRISTIAN KBKMER, asubject of the Emperor of Germany. residing at Berlin, Germany, haveinvented certain new and useful Improvements in Motor-Control Systems,of which the following is a specification.

This invention relates to devices for con trolling electric motors andhas for its object the provision of means whereby an electric motor maybe cont-rolled from a remote point in a simple and reliable manner.

My invention relates more specifically to the control of motors whichare employed for operating rudders, Searchlight projectors and the like,the object being to provide means whereby the movement of thetransmitting mechanism in the hands of an operator at a remote pointwill be reproduced at the motor. Devices of this kind have been commonlyused, but some of them have the objection that a large number ofconductors are necessary between the transmitting and receiving stationsin order to obtain an equal number of control positions. Thetransmitting and receiving stations are frequently long distances apartand the provision of alarge number of conductors is not onlyinconvenient, but also expensive.

One of the objects of my invention, therefore, is to reduce the numberof conductors, at the same time insuring accurate and efficient controlthroughout a large number of control points.

Other objects and purposes of my invention will appear in the course ofthe following specification in which I have shown my invention embodiedin concrete form for purposes of illustration.

In the accompanying drawing which illustrates my invention in concreteform, Figure 1 shows diagranmiatically the form of device to which myinvention is to be applied; Fig. 2 is a diagrammatic view of one form ofmy invention; Fig. 3 is a view of the apparatus similar to that shown inFig. 2; and Figs. 4, 5 and 6 are modified forms of my invention.

Referring first to Fig. 1, it will be seen that this figure represents atypical form of apparatus to which my improvement is applicable. In thisfigure, A represents the armature and f and f the two fields of themotor, either one of which may be in circuit to drive the motor in theforward or reverse direction. This motor is controlled from a remotepoint by a transmitting device T consisting of a plurality of contacts,a, b, 0, d, e, and a controlling contact arm 10 which is moved over thecontacts by the operator. The receiving device R consists of thecontroller C driven by the motor in any manner, as, for instance,through the worm gearing shown. The controller consists of twoconducting segments 11 and 12 insulated from each other. For purposes ofillustration, I have shown two segments separated by an air space,although, of course, in practice other forms of insulation may be moresuitable. Cooperating with these contacts are a plurality of brushes, a,b, 0", d, e-, connected by wires with the contacts on the transmittingdevice having corresponding reference characters.

and 12 by brushes l3 and 14. It will be seen that with the parts in theposition shown no current can flow to the field of the motor since thecontact 0 is in the oif position. If, however, the arm 10 is moved on tocontact til then a circuit will be completed from the positive side ofthe line through the contact d, thence to contact d, field f, motorarmature, to the other side of the line. This will cause the motor torotate in the direction indicated by the arrow until the brush (5 isopposite the space, whereupon the motor will stop. In like manner, ifthe controller is moved on to the contact 6 the controller may be drivenby the motor a corresponding amount until the circuit is opened at thecontact a. It the contact arm 16 is moved to the left into engagementwith the contacts I) or a the controller will be moved in the oppositedirection by the energization of the field f. It will be observed thatwith this device only as many 1 positions can be transmitted from thetransmitting device to the motor as there are conductors extendingbetween the two devices; in this case five.

In Fig. 2 I have shown means whereby the number of positions transmittedmay be greatly increased without substantially in creasing the number oftransmitting wires. Referringto this figure, which is diagrammat-inmerely, the contacts a, b, 0, d, e of the These brushes are of lesswidth than the space between the seg- 25- tween the contact plates 23and 24.

transmitting device T are connected with the corresponding contacts a",b, ii, 6 of the receiving device R, by wires 15, 16, 17, 18 and 19through the resistances 20. Contacts (1, b, 0. d and e in this casemaybe stationary, while the movable part of the transmit.

ting device consists of the two contact 7 plates 21 and 22 which arespaced from each other a distance which is greater than the 0 width ofthe cooperating contacts. On each side of the contacts a, b, c, d, e arecontact plates 23 and 24 connected with the contact plates 21 and 22 bywires 25 and 26 and the fields f and f of the motor are connected withconductors 27 and 28 at 29 and 30.

Current is supplied to the receiving device R through the device Tconsisting of a contact arm connected with the positive side of the lineand cooperating with the contacts g,

h and 2'. These contacts g, h and z" are conthe brush 2" is at thebeginning of contact plate 24. With the parts in the position 80 shownin Fig. 2 the field circuit of the motor is open at the contact a. If,however, the movable part of the transmitting device, namely, thecontacts 21 and 22, is moved to the right the circuit will then beclosedfrom the positive side of the line to the cont-act h,

thence to brush it on the receiving device and contact a, thence wire 15and contact plate 21 to wire 25 and field f ,to the negative side of theline.

and 24, and the intervening contacts, to move to the left until thebrush it engages contact b. In this position the motor will be stopped,since the circuit is opened at the brush 6. In like manner, as thetransmitting deviceis moved through the five positions, the receivingdevice will be correspondingly moved until the contact (1' engages thebrush g' If now the auxiliary transmitting device T is moved onto thecontact 9 then the brush 9 will be supplied with current and thereceiving device will be moved through five steps more. In the same wayif the auxiliary transmitting device is moved so that the contact i isconnected with the positive side of the line, then the brush 2" will besupplied with current and five more positions will be provided. In otherwords, the number of positions the motor will be afforded by saiddevioe'will be the product of the number of conductors between thereceiving and transmitting device, in this case five, and the number ofconductors from the supply circuit to the receiving device, which inthis case is three,

This will cause the re- 40 ceiving device, consisting of the plates 23making fifteen positions. It will be under- I stood, of course, thatthese controlling devices are in practice circular in form so that thecontact 6 of the device T, for instance passes oil the insulating spacebetween contacts 21 and 22 just as contact apasses onto it... Thisisbest understood by reference to Fig. 3, in .which the variouscontrolling devices are shown in proper form and relation to each other.In this case the controller of the receiving device consists of theplates 23 and 24: separated by the four contacts a, b, 0, d, which areconnected with the brushes 0, b, c and d of the transmitting device T bymeans of the four wires. Contact plates 21 and 22 are movable with thearm 10. The auxiliary tiansmitting device T consists of five contacts g,h, z, j, it connected with brushes g, h, i, j, 70 of the receivingcontroller by five separate wires as shown.

The movable arm of the auxiliary transmitting device'T is connected withthe positive side of the line. By moving the arm 31 into engagement withany one of the con- I tacts g, h, i, '9', 70, any one of the brushes g,h, i, j, 70' will be energized. The fields f and f are connected withplates 23 and 24 by brushes 32 and 33. The two devices T and T aremechanically connected with each other so that to each half revolutionof the arm 10 the arm 31 will complete a revolution, that is, the ratioof the movements between the two arms is two to five. With the parts inthe position shown in Fig. 3 no circuit is closed since the brush a"which is energizedconnects with brush contact d which is dee-nergized.If now thearm 10 is moved to the right the segment 21 will move intoengagement with the brush d so as to bein connection with brush 32 andfield Then the field f of the motor will be energized through brushes zand z" to'contacts d, d, and contact 34 to field f. This will cause themotor to rotate so as to rotate the controller drum in the direction ofthe arrow until the brush 2'' passes off contact d and onto contact 0'.The motor will then be stopped, since the contact 0 is not now incircuit. In like manner, by moving the arm 10 so that the segment 21engages the brushes 0, b and a respectively, the controller will becorrespondingly moved. In the meantime the arm 31 of the transmittingdevice T" is moved forward along the contact z until it engages thecontact 7', whereupon the brush 9" will be energized and the contacts a,b, 0 and d will pass under this brush and operate as before. In thiscase it will be seen that for each position of the transmitting device Tfour positions will be transmitted. Since there are five positions ofthe transmitting device T, twenty positions in all can be transmitted tothe receiving controller.

In Fig. 4 I have shown a slight modificat-ion which consists principallyin employ ing the Ward-Leonard system of control .instead of controllingthe motor'directl The two windings f and f are the fie d windings of thegenerator G which furnishes current to the armature A of the motor.recion or the other, depending upon which of the two fields f or f isenergized.

In Fi 5 I have shown another modification in which the two coils f and fare the coils of a relay, either of which may be energized to cause therelay to close the circuit to connect the motor for rotation in onedirection or the other.

In the arrangement shown in Fig. 6 not only the transmitting mechanismis divided into two parts, devices T and T, but the receiving mechanismis likewise divided into two parts, R and R. The controlling device T,which is connected with the positive side of the line, is provided witha plurality of contacts, A, B, O, D, E connected by wires withcorresponding brushes A, B, C, D and E on the receiving device R. Whilein the form shown in Fig. 3 a number of contacts are inserted betweenthe segments 23 and 24c for producing the intermediate positions betweenthe main positions, in the present instance there is only a singlecontact bar 35having a length equal to the distance between the brushesA and B, etc. This segment 35 is connected by a brush to wire 36 to thepivotal point of the movable member of the transmitting device T. Thistransmitting device T consists of five contacts, F, G, H, I, J,connected by wires with corresponding brushes F, G, H, I, J, K on thereceiving controller R. This controller is arranged as in Fig. 1 andconsists merely of two segments 11 and 12 and is driven by the motor M.The brushes 32 and 33 are likewise'in engagement with the contactsegments 11 and 12 and connect through the resistances r and 7" with thefields f and f, which in this instance I have shown merely as being thefields of the exciter X for the generator Y which supplies the motor.The two receiving devices It and R are connected together mechanicallyin such a manner that during one-half revo lution of the receivingdevice It the receiving device R rotates half a brush. The twotransmitting devices are so connected mechanically that during acomplete rotation. of the device T the transmitting device T is rotatedone contact. lVit-h the parts as shown. in. the drawing the circuit isfrom the positive side of the line through the contact C, to the brush Gof the receiving device R, segment 35, conductor 36, to the contact H"and to brush II. If now the arm of the transmitting device T is moved onto contact I then the brush I of the receiving device It willbeenergized and cur- The motor will be driven in one di-,

rentwill pass to the segment-1 12, brush 33, I

resistance r and field f; This'istarts the motor thereby shifting the seout 12 to such a position as to interrupt .t e'circ'mitat contact brushI. This process will be repeated until the contact device T is movedceiving device and from there directly to the field f of the exciter.The motor M is thus started and rotates the contact segments 11 and 12'of the receiving device It in the direction of the arrow. .At theinstant when the segment 11 connects the brushes F and H the receivingdevice R rotates one brush division farther. This is caused by the factthat the brush D simultaneously engages. the segments 23 and 35. Thiscauses a divided current to flow through the conductor 36, contact F,contact F, thence to the resistance r, and field f. Since, however, onaccount of the resistance r, the energization of the field f is lessthan that of the field f, the motor will continue to rotate in the samedirection until the brush F passes oil the segment 11. By furthermovement of the transmitting device T the receiving device R will bemoved correspondingly. -Attention is here called to the function of theresistances r and r. The transmitting device T must be adapted to bemoved to any position without regard to the position of the contact andduring these movements current interruptions must not occur in passingfrom one to the other. This is obvious since otherwise the control lingarm might stop at some position, as for instance between contacts J andF, and the controlling arm of the transmitting device T would finditselfbetween the contacts D and E. If in this case interruption ofcurrent should occur the. motor M would not be moved and the devicewould be destroyed. Thus in order that no interruption of current maytake place two contacts must be engaged simultaneously. Assume in thiscase that the arm of the transmitting device T touches simultaneouslythe contacts C a'nd'D while the controlling arm of the transmittingdevice T touches simultaneously contacts J and F, the receiving device Rbeing in the position indicated on the drawing. Current flows from thepositive side of the line throughthe contacts 0 and D in parallel,thence to the contacts C and D in parallel. From the brush D currentpasses directly to the field f of the motor, exciting the latter whilefrom the brush C current passes through the conductor 36 to the brushesJ and F, and thence in parallel to the brushes J and F of the receivingdevice R. The field f is thus energized through the resistance r andsince the resistance 1" is practically short circuited, the field f willbe almost fully energized. If the resistarice two fields would beequally and oppositely energized. The motor therefore rotates in adirection corresponding to the excitation of the field f but themovement is correspondingly slower. The motor will therefore move untilthe contact segment 11 connects the brushes F and J, brushes-C and D atthe same time both touching the contact 35. At this instant the twofields f and f are equally and oppositely excited and the motor andreceiving device remain in this intermediate position which correspondsto the intermediate position of the transmitting device. It will thus beseen that by the use of the resistances r and r movements are etiectivalso at the intermediate positions.

It will thus be seen that I have provided tion, the scope of which isset forth in the annexed claims. i

What I claim as new and desire to secure by Letters Patent of the UnitedStates,-is,-

1. The combination with an electric-motor, of a controller therefordriven by the motor, a transmitting device, .a plurality of conductorsconnecting said controller with the transmitting device, a plurality ofconductors supplying current from the source "of supply to thecontroller, and connections whereby said controller is moved by themotor in response to a movement of the transmitting device to a numberof positions equal to the product of the two sets of conductors. v

2. The combination with an electric motor, of a controller therefordriven by the motor having a plurality of contacts, a transmittingdevice provided with corresponding contacts, a plurality of conductorsconnecting the contacts on the controller with the correspondingcontacts on the transmittin tors supplying current from a source ofsupply to the contacts on the controller, and connections whereby saidcontroller is moved by the motor in response to a movement of 1' werenot provided the,

device, a plurality of conducthe transmitting device to a number ofpositions equal to the product of the two sets of conductors.

3. The combination with an electric motor, of a controller therefordriven by the motor and provided with a plurality of contacts, atransmitting device provided with corresponding contacts, a plurality ofconductors connecting the contacts on the con-- troller with thecorresponding contacts on the transmitting device, a plurality of conductors connecting the controller with a source of supply, a switch forshifting from one supply conductor to another, and connections whereby.the controller is moved throughout the range of its contacts inresponse to corresponding movement of the transmitting device when onesupply conductor is in circuit and repeats the o eration when anothersupply conductor is in circuit;

4. The combination with an electric motor, of'a controller therefordriven by the motor and provided with a plurality of contacts, atransmitting device provided with corresponding contacts, a plurality ofconductors connecting the contacts on the controller with thecorrespondingcontacts on the transmitting device, a plurality ofconductors connecting the controller with a source of supply, a switchfor shifting the connection of the source of supply from one conductorto another, mechanical connections between the switch and said devicewhereby the latter is moved over a number of contacts while the formeris being moved to its next contact, and connections whereby thecontroller is moved to a number of positions equal to the product of thesaid sets of conductors in responsev to corresponding movements of thetransmitting device.

5. The combination with an electric motor. and a controller therefordriven by the motor having a plurality of contacts, a transmittingdevice comprlsing a maincontact device having contacts correspondingwith those on the controller, and an auxiliary contact devicemechanically connected therewith so that. the former moves throughoutits entire range of movement while the latter is moving to the nextcontact, a plurality of conductors connecting the contacts on thecontroller with corresponding contacts on the main contact device, alurality of conductors supplying current rom the auxiliary contactdevice to the contacts on the controller, and connections whereby thecontroller is moved throughout its range of contacts in response to acorresponding movement of the main contact device in position of theauxiliary contact device.

6. The combination with an electric motor and a controller therefordriven by the motor and provided with a plurality of contacts, atransmitting device provided with contacts corres onding with those onthe controller, a p urality of conductors connecting the contacts of thecontroller to corresponding contacts on the transmitting device, brushesconnected with a source of supply cooperating with't-he controllercontacts and arranged so that one brush engages the first contact whenanother passes off the last contact, a switch for shifting tlfeconnection of the source of supply from one brush to another, andconnections whereby a movement is given the controller throughout itsrange of contact in response to movement oi the transmitting device aseach'brush is connected to the supply circuit.

7. The combination with an electric inotor and a controller therefordriven by the motor having a plurality of contacts, a transmittercomprising a main contact device having contacts corresponding withthose on the controller, an auxiliary contact device connected with asource of supply, mechanical connections between said two deviceswhereby the main contact device is Inoved throughout its entire range ofmovement while the auxiliary device is moving to its next contact, aplurality of conductors connecting the contacts on the controller withcorresponding contacts on the main contact device, a plurality ofconductors between the auxiliaryscontact device and the controllerarranged so that they supply current one aftenanother to the successivecontacts of the controller. In; witness whereof, I have hereunto set myhand this 14th day of May, 1912.

CHRISTIAN KRAMER. Witnesses:

RICHARD VENMANN, WALTHER REINHARDT.

